The present invention relates to cathodic protection of iron piping systems and the fittings therefor for use in aggressive soil environments. In particular, the invention relates to a simple system for adding sacrificial metal anodes to such systems and fittings.
Corrosion protection of iron piping systems and metal tanks by means of sacrificial anodes is well known. The most common practice places sacrifical anodes along side the tank or pipe line and electrically connects the anodes thereto. Because of the different metal of the pipe line and the sacrificial anodes, the anodes are sacrificed and will protect the pipe line or tank against corrosion until the anodes have been depleted. These systems work satisfactorily, however they do require care and skill in installation. Therefore there still remains a need for a cathodic protection system for ductile iron piping and the like which is simple and can be installed with relatively unskilled labour.
Other examples of known cathodic protection for various applications are exemplified in U.S. Pat. No. 2,974,389 Tatum which discloses a metal casket having sacrificial anodes attached thereto, U.S. Pat. No. 3,574,080 Jones et al which discloses a unique screw fastener having a portion thereof of sacrificial metal and U.S. Pat. No. 1,646,736 Mills which discloses a combination pipe connector and sacrificial metal anode.
The above listed patents are examples of more complicated structures which although installation of the cathodic protection is simplified, the manufacturing cost of the various structures disclosed is greatly increased. Therefore, the ease of installation must be accomplished while still providing a structure for a sacrificial anode which is easily manufactured. Furthermore, sacrificial anodes if used in a fitting must be such that the securement of the fitting to the pipe lines remains intact even after the sacrificial anode has been depleted.
The present invention provides a corrosion protection system for ductile iron sectional buried piping systems which is easily installed while providing a structure which can be manufactured at low cost. The sacrificial anode may be secured to individual lengths of piping prior to installation in the system, or the anodes can be secured during the installation thereof. There is no requirement for skilled expertise during the installation and the anode can be connected in a manner to protect a number of sections of pipe simultaneously.